Electronic structure having a transformer

ABSTRACT

An electronic structure comprising: a circuit board, wherein electronic devices and a transformer are disposed on the circuit board, wherein the transformer comprises a first coil, a second coil, and a magnetic body comprising a pillar with at least one portion of the pillar being disposed in a through-opening of the circuit board, wherein the first coil is wound around an upper portion of the pillar and the second coil is wound around a lower portion of the pillar for forming the transformer.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.16/870,969 filed on May 10, 2020, which claims the benefit of U.S.Provisional Application Ser. No. 62/983,765 filed on Mar. 2, 2020, eachof the above-mentioned applications is hereby incorporated by referenceherein and made a part of the specification.

BACKGROUND OF THE INVENTION I. Field of the Invention

The invention relates to an electronic structure and, in particular, toan electronic structure with a transformer.

II. Description of the Related Art

Electronic structures, such as a power supply module with differentpower domains, usually need a transformer to decouple voltages indifferent power domains so that the electronic devices in one powerdomain will not be affected by the voltages of the other power domain inthe power supply module. However, a conventional power supply modulewith a transformer requires a large space for accommodating thetransformer and the electronic devices in the power supply module.Besides, the design process of the electronic structure, such as thepower supply module, is complicated and costly. Furthermore, it iseasier to cause abnormal voltages in the power supply module due to theshort distance between the transformer and the electronic devices in thepower supply module as the size of the power supply module becomessmaller and smaller.

Accordingly, there is a demand for a better solution to resolve theaforementioned issues.

SUMMARY OF THE INVENTION

One objective of the present invention is to provide an electronicstructure comprising a pillar with at least one portion of the pillarbeing disposed in a through-opening of a circuit board, wherein twocoils are wound around the pillar for forming a transformer.

One objective of the present invention is to provide an electronicstructure with a smaller size by using conductive patterns of a circuitboard to form a first coil and a second coil of a transformer.

One objective of the present invention is to provide a transformer byusing a flexible printed circuit board (FPCB) to form a first coil and asecond coil of a transformer to reduce the size of the transformer.

In one embodiment, an electronic structure is disclosed, wherein theelectronic structure comprises: a circuit board, wherein a plurality ofelectronic devices and a transformer are disposed on the circuit board,wherein the transformer comprises a first coil, a second coil, and amagnetic body, wherein the magnetic body comprises a first portiondisposed in a first hollow space of the first coil and a second portionin a second hollow space of the second coil for forming the transformer.

In one embodiment, a molding body encapsulates at least one portion ofthe outer surface of the first coil, at least one portion of the outersurface of the second coil, and the plurality of electronic devices forelectrically isolating the plurality of electronic devices from thetransformer.

In one embodiment, the molding body comprises a resin.

In one embodiment, the molding body comprises epoxy.

In one embodiment, the molding body encapsulates the entire outersurface of the first coil.

In one embodiment, the molding body encapsulates the entire outersurface of the second coil.

In one embodiment, the molding body further encapsulates at least oneportion of the outer surface of the magnetic body.

In one embodiment, the molding body further encapsulates the entireouter surface of the magnetic body.

In one embodiment, each of the first coil and the second coil is formedby corresponding conductive patterns of a plurality of conductive layersof the circuit board.

In one embodiment, the first coil comprises a first plurality ofconductive patterns on the top surface of the circuit board, and thesecond coil comprises a second plurality of conductive patterns on thetop surface of the circuit board, wherein the molding body encapsulatesthe first plurality of conductive patterns and the second plurality ofconductive patterns.

In one embodiment, the first coil comprises a first plurality ofconductive patterns on the top surface of the circuit board and a secondplurality of conductive patterns on the bottom surface of the circuitboard, wherein the molding body encapsulates the first plurality ofconductive patterns and the second plurality of conductive patterns.

In one embodiment, the first coil comprises a first plurality ofconductive patterns on the top surface of the circuit board, a secondplurality of conductive patterns on a middle layer of the circuit boardand third plurality of conductive patterns on the bottom surface of thecircuit board, wherein the molding body encapsulates the first pluralityof conductive patterns, the second plurality of conductive patterns andthe third plurality of conductive patterns.

In one embodiment, the circuit board further comprises a plurality ofconductive patterns on the circuit board to electrically connect thefirst coil and an electronic device of the plurality of the electronicdevices.

In one embodiment, the circuit board comprises a BT (BismaleimideTriazine) substrate, metallic substrate or ceramic substrate.

In one embodiment, the circuit board is a multilayer circuit board,wherein the first coil comprises corresponding conductive patterns oneach layer of the multilayer circuit board, wherein the molding bodyencapsulates the corresponding conductive patterns on each layer of themultilayer circuit board.

In one embodiment, the second coil comprises a second plurality ofconductive patterns on each layer of the multilayer circuit board,wherein the molding body encapsulates the first plurality of conductivepatterns and the second plurality of conductive patterns.

In one embodiment, the plurality of electronic devices are embeddedinside the multilayer circuit board.

In one embodiment of the present invention, a high-density circuitdesign can be obtained by embedding the plurality of electronic devicesinside the circuit board, wherein active components or passivecomponents can be embedded inside the circuit board; the circuit boardcan be a single-sided circuit or a double-sided circuit design, whereinthe embedded design can effectively shorten the conductive path betweencomponents to achieve higher efficiency, smaller size and higher densityof the circuit design.

In one embodiment, each of the first coil and the second coil is formedby a conductive wire.

In one embodiment, one portion of the first coil is disposed above thecircuit board and another portion of the first coil is disposed belowthe circuit board.

In one embodiment, the first coil is disposed above the circuit boardand a third coil is disposed below the circuit board, wherein the firstcoil is electrically connected to the third coil by a conductive patternof the circuit board.

In one embodiment, each of the first coil and the second coil isdisposed in a through-opening of the circuit board.

In one embodiment, each of the first coil and the second coil isdisposed in a recess of the circuit board.

In one embodiment, each of the first coil and the second coil isdisposed in a recess of the circuit board.

In one embodiment, the plurality of electronic devices comprise an IC.

In one embodiment, an electronic structure is disclosed, the electronicstructure comprising: a circuit board, wherein a plurality of electronicdevices and a transformer are disposed on the circuit board, wherein thetransformer comprises a first coil, a second coil, and a magnetic body,wherein the magnetic body comprises a first portion disposed in a firsthollow space of the first coil and a second portion in a second hollowspace of the second coil for forming the transformer, wherein each ofthe first coil and the second coil is formed by corresponding conductivepatterns of a plurality of conductive layers of the circuit board.

In one embodiment, an electronic structure is disclosed, the electronicstructure comprising: a first coil, a second coil, and a magnetic body,wherein the magnetic body comprises a first portion disposed in a firsthollow space of the first coil and a second portion in a second hollowspace of the second coil for forming the transformer, wherein each ofthe first coil and the second coil is formed on a flexible printedcircuit board.

In one embodiment, a plurality of electronic devices are disposed on theflexible printed circuit board.

In one embodiment, each of the first coil and the second coil is formedby corresponding conductive patterns of the flexible printed circuitboard.

In one embodiment, each of the first coil and the second coil is formedby a corresponding conducting wire.

In one embodiment, a molding body comprising an insulating material toencapsulate at least one portion of the first coil, at least one portionof the second coil, and the plurality of electronic devices disposed onthe flexible printed circuit board.

In one embodiment, the first coil comprises a first plurality ofconductive patterns on the top surface of the flexible printed circuitboard and a second plurality of conductive patterns on the bottomsurface of the flexible printed circuit board, wherein the firstmagnetic molding body encapsulates the first plurality of conductivepatterns and the second plurality of conductive patterns to form thetransformer.

In one embodiment, a transformer is disclosed, the transformercomprising: a flexible printed circuit board, wherein a first coil and asecond coil are formed by a plurality of conductive patterns of theflexible printed circuit board, wherein a magnetic body comprises afirst portion disposed in a first hollow space of the first coil and asecond portion in a second hollow space of the second coil for formingthe transformer.

In one embodiment, the first coil comprises first plurality ofconductive patterns on the top surface of the flexible printed circuitboard and second plurality of conductive patterns on the bottom surfaceof the flexible printed circuit board, wherein the first magneticmolding body encapsulates the first plurality of conductive patterns andthe second plurality of conductive patterns to form the transformer.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more fully understood by reading thesubsequent description and examples with references made to theaccompanying drawings, wherein:

FIG. 1A is a top view of an electronic structure according to oneembodiment of the invention;

FIG. 1B is a bottom view of the electronic structure of FIG. 1Aaccording to one embodiment of the invention;

FIG. 1C is a cross-sectional side view of the electronic structureaccording to one embodiment of the invention;

FIG. 1D is a cross-sectional side view of the electronic structureaccording to one embodiment of the invention;

FIG. 1E is a cross-sectional side view of the electronic structureaccording to one embodiment of the invention;

FIG. 1F is a cross-sectional side view of the electronic structureaccording to one embodiment of the invention;

FIG. 1G is a cross-sectional side view of the electronic structureaccording to one embodiment of the invention;

FIG. 1H is a cross-sectional side view of the electronic structureaccording to one embodiment of the invention;

FIG. 1I is a cross-sectional side view of the electronic structureaccording to one embodiment of the invention;

FIG. 2A shows a cross-sectional side view of an electronic structureaccording to one embodiment of the invention; and

FIG. 2B shows a cross-sectional side view of an electronic structureaccording to one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

It is understood that the following disclosure provides many differentembodiments, or examples, for implementing different features of theinvention. Specific examples of devices and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features are formed between the first and second features,such that the first and second features are not in direct contact.Besides, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for simplicity andclarity and does not in itself dictate a relationship between thevarious embodiments and/or configurations discussed.

FIG. 1A is a top view of an electronic structure according to oneembodiment of the invention. FIG. 1B is a bottom view of the electronicstructure of FIG. 1A. FIG. 1C is a cross-sectional side view of theelectronic structure of FIG. 1A. As shown in FIG. 1A-1C, wherein theelectronic structure comprises: a circuit board 101, wherein a pluralityof electronic devices 103 and a transformer 102 are disposed on thecircuit board 101, wherein the transformer 102 comprises a first coil102 a, a second coil 102 b, and a magnetic body 102 c, wherein themagnetic body 102 c comprises a first portion disposed in a first hollowspace of the first coil 102 a and a second portion in a second hollowspace of the second coil 102 b for forming the transformer 102, whereina molding body 105 encapsulates at least one portion of the outersurface of the first coil 102 a, at least one portion of the outersurface of the second coil 102 b and the plurality of electronic devices103, wherein the molding body 105 is capable of electrically isolatingthe plurality of electronic devices 103 from the transformer 102 andincrease the structural strength of the electronic structure.

In one embodiment, the molding body 105 comprises a resin

In one embodiment, the molding body 105 comprises epoxy.

In one embodiment, the molding body 105 is integrally formed and has aunitary body.

In one embodiment, the molding body 105 encapsulates the entire outersurface of the first coil 102 a.

In one embodiment, the molding body 105 encapsulates the entire outersurface of the second coil 102 b.

In one embodiment, the molding body 105 further encapsulates at leastone portion of the outer surface of the magnetic body.

In one embodiment, the molding body 105 further encapsulates the entireouter surface of the magnetic body.

In one embodiment, each of the first coil 102 a and the second coil 102b is formed by corresponding conductive patterns 107 of a plurality ofconductive layers of the circuit board 101, as shown in FIG. 1C.

In one embodiment, the circuit board 101 is a single side PCB, whereinthe conductive patterns are in the top or the bottom surface of thecircuit board.

In one embodiment, the circuit board 101 is a double side PCB, whereinthe conductive patterns are in the top and the bottom surface of thecircuit board.

In one embodiment, the circuit board 101 is a multilayer PCB wherein theconductive patterns are on the top surface, at least one middleconductive layer, and the bottom surface of the circuit board.

In one embodiment, at least one portion of the magnetic body 102 c isdisposed in a through-opening of the circuit board.

In one embodiment, the first coil 102 a comprises a first plurality ofconductive patterns on the top surface of the circuit board 101, and thesecond coil 102 b comprises a second plurality of conductive patterns onthe top surface of the circuit board 101, wherein the molding body 105encapsulates the first plurality of conductive patterns and the secondplurality of conductive patterns.

In one embodiment, the first coil 102 a comprises a first plurality ofconductive patterns on the top surface of the circuit board 101 and asecond plurality of conductive patterns on the bottom surface of thecircuit board 101, wherein the molding body 105 encapsulates the firstplurality of conductive patterns and the second plurality of conductivepatterns.

In one embodiment, the first coil 102 a comprises a first plurality ofconductive patterns on the top surface of the circuit board 101, asecond plurality of conductive patterns on a middle layer of the circuitboard 101, and a third plurality of conductive patterns on the bottomsurface of the circuit board 101, wherein the molding body 105encapsulates the first plurality of conductive patterns, the secondplurality of conductive patterns and the third plurality of conductivepatterns.

In one embodiment, the circuit board 101 further comprises a pluralityof conductive patterns to electrically connect the first coil 102 a andat least one electronic device of the plurality of the electronicdevices 103.

In one embodiment, the circuit board comprises a BT (BismaleimideTriazine) substrate, metallic substrate or ceramic substrate.

In one embodiment, the width W of the circuit board 101 is 33 mm and thelength L of the circuit board 101 is 18 mm, and the size of the circuitboard is reduced 34% compared with the conventional power supply module.

In one embodiment, the circuit board 101 is a multilayer circuit board,wherein the first coil 102 a comprises corresponding conductive patternson each layer of the multilayer circuit board, wherein the molding body105 encapsulates the corresponding conductive patterns on each layer ofthe multilayer circuit board.

In one embodiment, the second coil 102 b comprises a second plurality ofconductive patterns on each layer of the multilayer circuit board,wherein the molding body 105 encapsulates the first plurality ofconductive patterns and the second plurality of conductive patterns.

In one embodiment, the plurality of electronic devices 103 are embeddedinside the circuit board 101.

In one embodiment, the circuit board 101 is a multilayer circuit board,wherein the plurality of electronic devices 103 are embedded inside themultilayer circuit board.

In one embodiment, each of the first coil 102 a and the second coil 102b is formed by a discrete conducting wire, as shown in FIG. 1G.

In one embodiment, the circuit board 101 comprises conductive patterns107 on the circuit board 101 to electrically connect the first coil 102a, the second coil 102 b and the plurality of the electronic devices103.

In one embodiment, one portion of the first coil 102 a is disposed abovethe top surface of the circuit board 101 and another portion of thefirst coil 102 a is disposed below the bottom surface of the circuitboard 101.

In one embodiment, the first coil 102 a is disposed above the circuitboard and a third coil is disposed below the circuit board 101, whereinthe first coil 102 a is electrically connected to the third coil by aconductive pattern of the circuit board 101. In one embodiment, each ofthe first coil 102 a and the third coil is formed by a correspondingconductive wire. In one embodiment, each of the first coil 102 a and thethird coil is formed by a corresponding insulated conductive wire, suchas an enameled wire.

In one embodiment, the magnetic body 102 c is disposed in athrough-opening of the circuit board 101.

In one embodiment, each of the first coil 102 a and the second coil 102b is disposed in a through-opening of the circuit board 101.

In one embodiment, each of the first coil 102 a and the second coil 102b is disposed in a recess of the circuit board 101.

In one embodiment, the plurality of electronic devices 103 comprise atleast one active device such as an IC or diode and at least one passivedevice such as a resistor, capacitor or an inductor.

In one embodiment, the plurality of electronic devices 103 are disposedon a top and/or a bottom surface of the circuit board 101.

In one embodiment, at least one portion of the plurality of electronicdevices 103 is embedded inside the circuit board 101, as shown in FIG.1F.

In one embodiment, the plurality of electronic devices 103 are entirelyembedded inside the circuit board 101.

In one embodiment, the plurality of electronic devices 103 compriseactive devices.

In one embodiment, the plurality of electronic devices 103 comprisepassive devices.

In one embodiment, the plurality of electronic devices 103 comprise anIC, as shown in FIG. 1C, such as a MOSFET.

In one embodiment, the plurality of electronic devices 103 comprise adiode, as shown in FIG. 1C.

In one embodiment, the plurality of electronic devices 103 comprise aresistor 103 b, as shown in FIG. 1C.

In one embodiment, the plurality of electronic devices 103 comprise acapacitor 103 c, as shown in FIG. 1C.

In one embodiment, the plurality of electronic devices 103 comprise aninductor.

In one embodiment, a plurality of electrodes 104 are disposed on thecircuit board 101 for electrically connecting with an external circuit.

In one embodiment, each of the plurality of electrodes 104 is asurface-mount pad on the circuit board 101 for electrically connectingwith an external circuit.

In one embodiment, one portion of the molding body 105 is disposed abovethe top surface of the circuit board 101, and another portion of themolding body 105 is disposed below the bottom surface of the circuitboard 101.

In one embodiment, each of the plurality of electrodes 104 is aconductive pin or a conductive pillar 104 a disposed on the bottomsurface of the circuit board 101 for electrically connecting with anexternal circuit, as shown in FIG. 1C. Please note that the conductivepin or a conductive pillar 104 a is capable of conducting a largecurrent, wherein the conductive pin or a conductive pillar 104 a can besurface mounted on an external motherboard.

In one embodiment, each of the plurality of electrodes 104 is a leadframe 104 b disposed on the circuit board 101 for electricallyconnecting with an external circuit, as shown in FIG. 1D. Please notethat the lead frame 104 b is capable of conducting a large current.

In one embodiment, each of the plurality of electrodes 104 is a stackedmetal bump 104 c disposed on the circuit board 101 for electricallyconnecting with an external circuit, as shown in FIG. 1E. Please notethat the stacked metal bump 104 c is capable of conducting a largecurrent.

In one embodiment, the molding body 105 encapsulates at least oneportion of the magnetic body 102 c of the transformer 102.

In one embodiment, the molding body 105 encapsulates the entire magneticbody 102 c of the transformer 102, as shown in FIG. 1E.

In one embodiment, one portion of the magnetic body 102 c of thetransformer 102 is disposed below the bottom surface of the molding body105, and another portion of the magnetic body 102 c of the transformer102 is disposed above the top surface of the molding body 105, as shownin FIG. 1G. In one embodiment, the first coil 102 a is disposed in afirst through-opening of the circuit board. In one embodiment, thesecond coil is disposed in a second through-opening of the circuitboard. In one embodiment, the first coil 102 a is disposed in a firstrecess of the circuit board. In one embodiment, the second coil isdisposed in a second recess of the circuit board.

In one embodiment, the circuit board 101 comprises one of the following:a PCB, a BT (Bismaleimide Triazine) substrate, a metallic substrate or aceramic substrate.

In one embodiment, the electronic structure comprises a multilayercircuit board that comprises the plurality of conductive patterns forforming the first coil 102 a and the second coil 102 b.

In one embodiment, the plurality of electronic devices 103 are embeddedinside the multilayer circuit board.

In one embodiment, each of the first coil 102 a and the second coil 102b is formed by a conductive wire, as shown in FIG. 1G. In oneembodiment, the conductive wire comprises a pre-wound coil formed by theconductive wire. In one embodiment, the conductive wire is an insulatedconductive wire. In one embodiment, the conductive wire is a roundconductive wire. In one embodiment, the conductive wire is a flatconductive wire. In one embodiment, each of the first coil 102 a and thesecond coil 102 b is formed by an enameled wire.

In one embodiment, each of the first coil 102 a and the second coil 102b is disposed in a through-opening of the circuit board 101.

In one embodiment, each of the first coil 102 a and the second coil 102b is disposed in a recess of the circuit board 101.

In one embodiment, the plurality of electronic devices comprise an ICsuch as a MOSFET.

In one embodiment, at least one portion of the plurality of electronicdevices 103, in FIG. 1G, is embedded inside the circuit board, as shownin FIG. 1H.

In one embodiment, the active devices of the plurality of electronicdevices 103, in FIG. 1G, are embedded inside the circuit board, as shownin FIG. 1H.

In one embodiment, at least one electronic device of the plurality ofelectronic devices 103 is electrically coupled to the first coil 102 a;and at least one electronic device of the plurality of electronicdevices 103 is electrically coupled to the second coil 102 b.

In one embodiment, the plurality of electronic devices 103 can compriseactive electronic devices, and passive devices such as a resistor, acapacitor or an inductor, wherein the active electronic devices cancomprises at least one of the following devices: a photo coupler, a Gan(Gallium-nitride) based HB (half bridge), an ACF (advanced adaptivedigital) controller, a SR (synchronous rectifier) controller, or aMOSFET, as shown in FIG. 1I.

In one embodiment, a photo coupler, a Gan (Gallium-nitride) based HB(half bridge) and an ACF (advanced adaptive digital) controller areelectrically coupled to the first coil 102 a; and a SR (synchronousrectifier) controller and a MOSFET are electrically coupled to thesecond coil 102 b, as shown in FIG. 1I.

In one embodiment, the molding body 105 encapsulates the plurality ofelectronic devices 103, a portion of the outer surface of the first coil102 a and a portion of the outer surface of the second coil 102 b, asshown in FIG. 1I.

In one embodiment, the molding body 105, which can be made of a moldingcompound, can have two portions on two opposite sides of the magneticbody 102 c, as shown in FIG. 1I. In one embodiment, the molding compoundcomprises a resin. In one embodiment, the molding compound comprisesepoxy.

In one embodiment, the magnetic body 102 c and the molding body 105 canbe separated by a gap g1, as shown in FIG. 1I.

In one embodiment, the magnetic body 102 c and the molding body 105 canbe separated by a gap g2, as shown in FIG. 1I.

In one embodiment, the magnetic body 102 c and the molding body 105 canbe separated by gaps g1, g2, as shown in FIG. 1I.

In one embodiment, the thickness T of the molding body 105, as shown inFIG. 1I, is not greater than 10 mm. In one embodiment, the thickness Tof the molding body 105 is 8.6 mm.

In one embodiment, as shown in FIG. 2A, the transformer 102 can beformed on a flexible printed circuit board 108, wherein each of thefirst coil 102 a and the second coil 102 b is formed by correspondingconductive patterns 108 a, 108 b of the flexible printed circuit board108, wherein the magnetic body 102 c comprises a first portion disposedin a first hollow space of the first coil 102 a and a second portion ina second hollow space of the second coil 102 b for forming thetransformer 102, wherein the transformer 102 formed on a flexibleprinted circuit board 108 can be disposed on the circuit board 101 as anintegrated component, wherein the flexible printed circuit board 108 iselectrically connected to the circuit board 101.

In one embodiment, as shown in FIG. 2A, the transformer can be formed ona flexible printed circuit board 108, wherein each of the first coil 102a and the second coil 102 b is formed by corresponding conductivepatterns 108 a, 108 b of the flexible printed circuit board 108, whereinthe magnetic body 102 c comprises a first portion disposed in a firsthollow space of the first coil 102 a and a second portion in a secondhollow space of the second coil 102 b for forming the transformer 102.

In one embodiment, a plurality of electronic devices 103 can be disposedon the flexible printed circuit board 108.

In one embodiment, a molding body 105 is disposed on the flexibleprinted circuit board 108 to encapsulate at least one portion of theouter surface of the first coil 102 a, at least one portion of the outersurface of the second coil 102 b and the plurality of electronic devices103 for electrically isolating the plurality of electronic devices 103from the transformer 102.

In one embodiment, the molding body 105 encapsulates at least oneportion of the magnetic body 102 c of the transformer 102.

In one embodiment, the molding body 105 encapsulates the entire magneticbody 102 c of the transformer 102.

In one embodiment, the flexible printed circuit board 108 is amultilayer circuit board, wherein the first coil 102 a comprisescorresponding conductive patterns 108 a on each layer of the multilayerflexible printed circuit board, wherein the molding body 105encapsulates the corresponding conductive patterns 108 a on each layerof the multilayer flexible printed circuit board.

In one embodiment, as shown in FIG. 1C, an electronic structure isdisclosed, wherein the electronic structure comprises: a circuit board101 a, wherein a plurality of electronic devices 103 and a transformer102 are disposed on the circuit board 101, wherein the transformer 102comprises a first coil 102 a, a second coil 102 b, and a magnetic body102 c, wherein the magnetic body 102 c comprises a first portiondisposed in a first hollow space of the first coil 102 a and a secondportion in a second hollow space of the second coil 102 b for formingthe transformer 102, wherein each of the first coil 102 a and the secondcoil 102 b is formed by corresponding conductive patterns of a pluralityof conductive layers of the circuit board 101 a.

In one embodiment, as shown in FIG. 2A and FIG. 2B, a transformer isdisclosed, wherein the transformer 102 comprises: a first coil 102 a anda second coil 102 b and a magnetic body 102 c, wherein each of the firstcoil 102 a and the second coil 102 b is disposed on the flexible printedcircuit board 108, wherein the magnetic body 102 c comprises a firstportion disposed in a first hollow space of the first coil 102 a and asecond portion in a second hollow space of the second coil 102 b forforming the transformer 102.

In one embodiment, each of the first coil 102 a and the second coil 102b is formed by corresponding conductive patterns of the flexible printedcircuit board 108, as shown in FIG. 2A.

In one embodiment, each of the first coil 102 a and the second coil 102b is formed by a corresponding conductive wire, as shown in FIG. 2B.

In one embodiment, the flexible printed circuit board 108 comprises aplurality of conductive patterns to electrically connect the first coil102 a to at least one portion of the plurality of the electronic devices103.

In one embodiment, the flexible printed circuit board 108 comprises aplurality of conductive patterns to electrically connect the second coil102 b to at least one portion of the plurality of the electronic devices103.

In one embodiment, the first coil 102 a comprises a first plurality ofconductive patterns on the top surface of the flexible printed circuitboard 108 and a second plurality of conductive patterns on the bottomsurface of the flexible printed circuit board 108, wherein the moldingbody 105 encapsulates the first plurality of conductive patterns and thesecond plurality of conductive patterns.

In one embodiment, as shown in FIG. 2A and FIG. 2B, an electronicstructure is disclosed, wherein the electronic structure comprises atransformer 102 formed on a flexible printed circuit board 108 and aplurality of electronic devices 103 that are disposed on the flexibleprinted circuit board 108, wherein the transformer 102 a comprises afirst coil 102 a, a second coil 102 b, and a magnetic body 102 c,wherein the molding body 105 encapsulates at least one portion of theouter surface of the first coil 102 a, at least one portion of the outersurface of the second coil 102 b and the plurality of electronic devices103 for electrically isolating the plurality of electronic devices 103from the transformer 102.

In one embodiment, each of the first coil 102 a and the second coil 102b is formed by corresponding conductive patterns of the flexible printedcircuit board, as shown in FIG. 2A.

In one embodiment, each of the first coil 102 a and the second coil 102b is formed by a corresponding conductive wire, as shown in FIG. 2B.

In one embodiment, the molding body 105 encapsulates the entire outersurface of the first coil 102 a and the entire outer surface of thesecond coil 102 b.

In one embodiment, the molding body 105 encapsulates the entire outersurface of the magnetic body 102 c of the transformer 102 formed on theflexible printed circuit board 108.

In one embodiment, the flexible printed circuit board 108 comprises aplurality of conductive patterns 107 to electrically connect the firstcoil 102 a and at least one portion of the plurality of the electronicdevices 103.

In one embodiment, the flexible printed circuit board 108 comprises aplurality of conductive patterns 107 to electrically connect the secondcoil 102 b and at least one portion of the plurality of the electronicdevices 103.

In one embodiment, the first coil 102 a comprises a first plurality ofconductive patterns on the top surface of the flexible printed circuitboard 108 and a second plurality of conductive patterns on the bottomsurface of the flexible printed circuit board 108, wherein the moldingbody 105 encapsulates the first plurality of conductive patterns and thesecond plurality of conductive patterns.

In one embodiment, as shown in FIG. 2A, a transformer is disclosed,wherein the transformer 102 comprises: a flexible printed circuit board108, wherein a first coil 102 a and a second coil 102 b are formed bycorresponding conductive patterns of the flexible printed circuit board108, wherein a magnetic body 102 c comprises a first portion disposed ina first hollow space of the first coil 102 a and a second portion in asecond hollow space of the second coil 102 b for forming the transformer102.

In one embodiment, the first coil 102 a comprises a first plurality ofconductive patterns on the top surface of the flexible printed circuitboard 108 and a second plurality of conductive patterns on the bottomsurface of the flexible printed circuit board 108, wherein the moldingbody 105 encapsulates the first plurality of conductive patterns and thesecond plurality of conductive patterns.

In one embodiment, the outer surface of the first coil 102 and the outersurface of the second coil 102 b are entirely encapsulated in themolding body 105.

In one embodiment, the first coil 102 a comprises a first plurality ofconductive patterns on the top surface of the flexible printed circuitboard 108 and a second plurality of conductive patterns on the bottomsurface of the flexible printed circuit board 108, wherein the moldingbody 105 encapsulates the first plurality of conductive patterns and thesecond plurality of conductive patterns.

In one embodiment, the flexible printed circuit board 108 comprises aplurality of conductive patterns 107 on the circuit board 101 toelectrically connect the first coil 102 a and the plurality of theelectronic devices 103.

In one embodiment, the flexible printed circuit board 108 comprises aplurality of electrodes 104 for electrically connect with an externalcircuit.

From the foregoing, it will be appreciated that, although specificembodiments have been described herein for purposes of illustration,various modifications may be made without deviating from the spirit andscope of the disclosure. Furthermore, where an alternative is disclosedfor a particular embodiment, this alternative may also apply to otherembodiments even if not specifically stated.

What is claimed is:
 1. An electronic structure, comprising: a circuitboard, wherein a plurality of electronic devices and a transformer aredisposed on the circuit board, wherein the transformer comprises a firstcoil, a second coil, and a magnetic body comprising a pillar with atleast one portion of the pillar being disposed in a through-opening ofthe circuit board, wherein the first coil is wound around an upperportion of the pillar and the second coil is wound around a lowerportion of the pillar for forming the transformer.
 2. The electronicstructure as claimed in claim 1, wherein the first coil comprises afirst plurality of winding turns, and the second coil comprises a secondplurality of winding turns.
 3. The electronic structure as claimed inclaim 1, wherein the first coil is formed by a first plurality ofconductive patterns of the circuit board.
 4. The electronic structure asclaimed in claim 3, wherein the second coil is formed by a secondplurality of conductive patterns of the circuit board.
 5. The electronicstructure as claimed in claim 4, wherein the circuit board comprises atleast one third conductive pattern to electrically connect the firstcoil and at least one electronic device of the plurality of theelectronic devices.
 6. The electronic structure as claimed in claim 4,wherein the first coil comprises at least one first conductive patternon the top surface of the circuit board.
 7. The electronic structure asclaimed in claim 6, wherein the second coil comprises at least onesecond conductive pattern on the bottom surface of the circuit board. 8.The electronic structure as claimed in claim 1, wherein the circuitboard comprises one of the following: a PCB, BT (Bismaleimide Triazine)substrate, metallic substrate or ceramic substrate.
 9. The electronicstructure as claimed in claim 1, wherein the plurality of electronicdevices are embedded inside the circuit board.
 10. The electronicstructure as claimed in claim 1, wherein the first coil is formed by afirst discrete conducting wire.
 11. The electronic structure as claimedin claim 10, wherein the second coil is formed by a second discreteconducting wire.
 12. The electronic structure as claimed in claim 11,wherein the circuit board comprises at least one first conductivepattern to electrically connect the first coil and at least one firstelectronic device of the plurality of the electronic devices.
 13. Theelectronic structure as claimed in claim 12, wherein the circuit boardcomprises at least one second conductive pattern to electrically connectthe second coil and at least one second electronic device of theplurality of the electronic devices.
 14. The electronic structure asclaimed in claim 11, wherein the first coil comprises a first pluralityof winding turns, and the second coil comprises a second plurality ofwinding turns.
 15. The electronic structure as claimed in claim 1,wherein the circuit board is a multilayer circuit board, wherein each ofthe first coil and the second coil is formed by corresponding conductivepatterns of the multilayer circuit board.
 16. The electronic structureas claimed in claim 1, wherein at least one electronic device of theplurality of electronic devices is electrically coupled to the firstcoil, and at least one electronic device of the plurality of electronicdevices is electrically coupled to the second coil.
 17. The electronicstructure as claimed in claim 1, wherein the plurality of electronicdevices comprise active electronic devices and passive devices.
 18. Theelectronic structure as claimed in claim 1, wherein the circuit board isa flexible printed circuit board, wherein at least one portion of thepillar is disposed in a through-opening of the flexible printed circuitboard.
 19. The electronic structure as claimed in claim 18, wherein eachof the first coil and the second coil is formed by correspondingconductive patterns of the flexible printed circuit board.
 20. Theelectronic structure as claimed in claim 19, wherein the flexiblecircuit board is a multilayer flexible printed circuit board.